[JStro23]

It doesn't matter if you use SE or XLR in, the amp uses a phase splitter and it "sees" 4v no matter what. The amp is designed to be used XLR out but using the lackluster SE will not cause an issue or a short. I don't know where this wrong info is coming from... Mostly likely the amp was just a dud. It happens.

Okay thank you. I was worried because I literally spent nine hours one night reading this thread, in addition to multiple days reading everywhere else I could find info and never saw that being brought up as a potential issue.

 

[Rattle]

Okay thank you. I was worried because I literally spent nine hours one night reading this thread, in addition to multiple days reading everywhere else I could find info and never saw that being brought up as a potential issue.

It's not an issue I've had 2 of these amps. I ran one for 3 years and puts over 1000 on it. Used it with an SE only DAC for hundreds of hours and always used XLR out.

 

[Jimmyblues1959]

It doesn't matter if you use SE or XLR in, the amp uses a phase splitter and it "sees" 4v no matter what. The amp is designed to be used XLR out but using the lackluster SE will not cause an issue or a short. I don't know where this wrong info is coming from... Mostly likely the amp was just a dud. It happens.

The only configuration that would cause the LP to short out would be using a balanced to single ended adaptor on the LP's XLR output.

 

[Rattle]

The only configuration that would cause the LP to short out would be using a balanced to single ended adaptor on the LP's XLR output.

Correct you never go XLR to SE on an XLR out of an amp. In other words XLR to SE adapters are a no no on XLR out of any amp.

 

[Jimmyblues1959]

Okay thank you. I was worried because I literally spent nine hours one night reading this thread, in addition to multiple days reading everywhere else I could find info and never saw that being brought up as a potential issue.

The point is that your headphones are inefficient so you want the most power you can get from the Liquid Platinum. That should be balanced input to balanced output.

 

[JStro23]

It's not an issue I've had 2 of these amps. I ran one for 3 years and puts over 1000 on it. Used it with an SE only DAC for hundreds of hours and always used XLR out.

That is good to know. I've been incredibly particular about following all instructions so didn't know if there was something I was missing. So it seems I may have just gotten a dud, because I made sure to buy the XLR for the heddphones specifically due to this amp running better though balanced. Alright, well I got another one on the way because I couldn't go without while I work out the problems with the first one with monoprice. So maybe I'll end up having two, and can use one of them to fiddle with odd tube configurations as some here have done. I've got some tubemonger sockets coming in and was looking forward to some tube rolling.

 

[JStro23]

The point is that your headphones are inefficient so you want the most power you can get from the Liquid Platinum. That should be balanced input to balanced output.

Yea they definitely are inefficient. Hence why this amp fits a fairly narrow niche that I wanted filled, a tube amp that has the power to drive inefficient cans (at this price point). I'll still look into picking up a basic converter box just to keep things even both in and out of the amp though. Just somewhat worried it may mess with sound quality using one of those.

 

[Rattle]

The point is that your headphones are inefficient so you want the most power you can get from the Liquid Platinum. That should be balanced input to balanced output.

There is no difference in "power" using SE in on the LP. Again it was designed using a phase splitter so it's see no difference in voltage. Try it. If you have a dac with both se and XLR hook em both up. There's no difference in volume.

 

[JStro23]

There is no difference in "power" using SE in on the LP. Again it was designed using a phase splitter so it's see no difference in voltage. Try it. If you have a dac with both se and XLR hook em both up. There's no difference in volume.

Oh good to know. Alright no signal converter then I guess. I appreciate your input.

 

[Jimmyblues1959]

Oh good to know. Alright no signal converter then I guess. I appreciate your input.
[/QUOTE
If the single ended and balanced inputs of the LP produce the same power output via the LP's balanced XLR output, then the only real advantage of the balanced input would be to prevent a ground loop.

 

[jonathan c]

I took off the small rubber feet which came with Liquid Platinum and put on four of these adhesive rubber feet:

Much better - taller, greater stability & contact area with the aftermarket feet below. Liquid Platinum runs only moderately warm.

 

[Jimmyblues1959]

I took off the small rubber feet which came with Liquid Platinum and put on four of these adhesive rubber feet: Much better - taller, greater stability & contact area with the aftermarket feet below. Liquid Platinum runs only moderately warm.

Standing taller and looking good!

 

[Ham Sandwich]

I was running on the balanced out, specifically bought the XLR having read Alex Cavelli's commentary about the circuitry in this thread a few years ago. So no adapters were used. The input in the back was into the RCA from an aux-rca adapter so I could run it from the line out on the DAC.

Edit: So is this most likely just a fluke then? I know I saw similar stories from some folks back earlier in this thread, and then others who have had no issues whatsoever. I really like the amp, and had put 15+ hours of listening in just the 3 days of use. I would be happy if the one I ordered to get me by during the return/refund/replacement process would just run smooth. Just got into these higher levels of hi-fi and am mesmerized.

Likely a fluke. There have been a few people mentioning early failures of the amp. But not regular thing and would seem to be very rare.

I bought a LP back when it was first released. It is now 5 1/2 years old. Used pretty much every day. It is still going strong. I've used it with both the single-ended inputs (RCA) and balanced inputs (XLR). And always with the balanced headphone out.

Your early failure is most likely due to either a tube failing or something in the electronics and circuitry inside the amp failing. An unfortunate reality of hybrid amps is that a tube failure can take out solid state components on the circuit board that kill the entire amp (like you saw with the magic smoke being released).

Do you have a guitar amp repair place or audio repair place that has a tube tester so you can find out if a tube failed? If a tube is bad then that could explain the damage (or maybe the tube failed because of the damage?). That would help answer what might have happened. The tubes that ship with the amp are brand new. The boxed have never been opened. And the tubes have never been checked after they left the factory. If you buy from a tube store and have the tubes tested for basic operation and measurements to get matched pairs you know that the tubes have been put in a tube tester and aren't bad tubes. But the tubes that ship with the LP have never been tested like that.

But more important is to contact Monoprice quickly and find out if they still have any amps in stock to do a warranty replacement.

If you are able to get a replacement I'd order tubes from a reliable tube store that tests the tubes. And use those tubes in the replacement amp. And never use the tubes that come with the LP. One of the tubes I got with my LP had an obviously misaligned pin (It would not have fit in a tube tester or the amp). I don't trust the tubes that come with the LP. Buy some replacement tubes that you can trust. Or take the stock tubes to someone who has a tube tester to make sure they're good before putting them in the amp.

 

[JStro23]

Likely a fluke. There have been a few people mentioning early failures of the amp. But not regular thing and would seem to be very rare.

I bought a LP back when it was first released. It is now 5 1/2 years old. Used pretty much every day. It is still going strong. I've used it with both the single-ended inputs (RCA) and balanced inputs (XLR). And always with the balanced headphone out.

Your early failure is most likely due to either a tube failing or something in the electronics and circuitry inside the amp failing. An unfortunate reality of hybrid amps is that a tube failure can take out solid state components on the circuit board that kill the entire amp (like you saw with the magic smoke being released).

Do you have a guitar amp repair place or audio repair place that has a tube tester so you can find out if a tube failed? If a tube is bad then that could explain the damage (or maybe the tube failed because of the damage?). That would help answer what might have happened. The tubes that ship with the amp are brand new. The boxed have never been opened. And the tubes have never been checked after they left the factory. If you buy from a tube store and have the tubes tested for basic operation and measurements to get matched pairs you know that the tubes have been put in a tube tester and aren't bad tubes. But the tubes that ship with the LP have never been tested like that.

But more important is to contact Monoprice quickly and find out if they still have any amps in stock to do a warranty replacement.

If you are able to get a replacement I'd order tubes from a reliable tube store that tests the tubes. And use those tubes in the replacement amp. And never use the tubes that come with the LP. One of the tubes I got with my LP had an obviously misaligned pin (It would not have fit in a tube tester or the amp). I don't trust the tubes that come with the LP. Buy some replacement tubes that you can trust. Or take the stock tubes to someone who has a tube tester to make sure they're good before putting them in the amp.

Yea I had an email sent to monoprice within 30 minutes of operation failure. I do in fact have a tube shop about an hour away from me I was intending to go to soon. If the tubes fail would they still run? If so I don't think it was tubes. Once I had let it sit for a while longer I tried the amp one more time, and by that point it would turn on and the tubes would warm up, but no sound would come through the amp any longer. I was unaware the tubes in the box were not at least factory tested prior to being placed in the box. I will definitely grab some different tubes the next go around. I already ordered another off amazon to get me by while working things out with monoprice on the first one, so I'll grab some tubes too. I'm just guessing it was some kind of short by the rca inputs based on what's still working and what isn't. Great sounding little amp otherwise. Kinda hoping I end up with 2 now and can use one for the experimental tube rolling I've seen others here do.

 

[Festive56]

Another general recommendation is to turn your volume all the way down before turning on your LP. I seem to remember Alex mentioning this way early in this thread as the outrush of current could activate the protection circuit. Just good housekeeping at any rate.